1. Field of the Invention
The present invention relates to a hydrogen sensor, a detection method for hydrogen concentration having the hydrogen sensor, and a motor vehicle having a fuel cell drive having has the hydrogen sensor.
2. Description of the Related Art
Hydrogen sensors normally measure a proportion of hydrogen in a gas or gas mixture using a principle of an electrochemical cell or chemically sensitive layers, for example a Lundstrom FET. These measurement principles are normally suitable for the detection of hydrogen.
One field of use for hydrogen sensors is motor vehicles with fuel cell drives. These motor vehicles require hydrogen sensors because hydrogen is highly flammable. It is therefore necessary to measure the concentration of hydrogen in the vicinity of motor vehicles with fuel cell drives.
Normally, there is a risk of explosion at atmospheric pressure with a proportion of hydrogen by volume of between 4% by volume and 77% by volume. These critical concentrations can occur in the event of a leak from the hydrogen tank or from a hydrogen line. For this reason, hydrogen sensors that monitor the hydrogen content in the surrounding area are an essential component of the safety architecture of a motor vehicle with a fuel cell drive.
One disadvantage of the hydrogen sensors mentioned initially using an electrochemical cell or chemically sensitive layers is that none of these sensors completely satisfy the requirements of the automobile industry in respect of life, measurement range, aging, cross-sensitivity, response time, measurement sensitivity and price.